1. Technical Field
The present invention relates to printed circuit boards, particularly to a method for manufacturing a rigid-flexible printed circuit board.
2. Description of Related Art
Rigid-flexible printed circuit boards (R-F PCBs) are widely used in electronic devices. Rigid-flexible printed circuit board has a rigid region and a flexible region. The rigid region is configured for assembling electronic components and maintaining electrical connections among the electronic components. The flexible region is connected to the rigid region and can be bent relative to the rigid region. Thus, a number of electronic components can be assembled on the rigid region of the rigid flexible printed circuit board without occupying a large amount of space.
A typical method for manufacturing a rigid-flexible printed circuit board is shown in FIGS. 7-10. As shown in FIG. 7, a rigid substrate 60 and a flexible substrate 70 are provided. The rigid substrate 60 has a first product region 61 and a first periphery region 62 around the first product region 61. The flexible region 70 has a second product region 71 corresponding to the first product region 61 and a second periphery region 72 corresponding to the first periphery region 62. As shown in FIG. 8, an opening 63 is formed in a predetermined position of the first product region 61 of the rigid substrate 60. As shown in FIG. 9, the rigid substrate 60 and the flexible substrate 70 are laminated to form a laminated substrate 8 having a predetermined region 81 and a pre-cut region 82. In detail, the first and second product region 61, 71 are laminated to form the predetermined region 81, the first and second periphery region 62, 72 are laminated to form the pre-cut region 82. In the predetermined region 81, a portion of the second product region 71 exposed from the opening 63 is adapted to form a flexible region, other portion of the second product region 71 laminated with the first product region 61 is adapted to form a rigid region. As shown in FIGS. 9-10, the laminated substrate 8 is cut along the boundary between the predetermined region 81 and the pre-cut region 82, thus the pre-cut region 82 of the laminated substrate 8 is removed and the predetermined region 81 forms a rigid-flexible printed circuit board 9 which has a flexible region 91 and a rigid region 92.
However, a material property of the rigid region 92 is different to that of the flexible region 91, when the pre-cut region 82 around the predetermined region 81 is removed simultaneously with a milling cutter, burrs may be formed on the margin of the flexible region 91. In addition, the thickness of the rigid region 92 is larger than that of the flexible region 91, thus, when the laminated substrate 8 is cut with the same cutting parameter, the cutting precision of the rigid region 92 and the flexible region 91 is different. Thus, the quality of the rigid-flexible printed circuit board 9 is affected.
What is needed, therefore, is a method for manufacturing the rigid-flexible printed circuit board which can overcome the above-described problems.